Resonance Raman and magnetic circular dichroism spectra of P450 model complexes (RS-FeP-O2, CO) will be compared with the enzyme spectra. Chemical and electrochemical properties under reductive conditions are to be examined to see if oxygen activation and insertion into substrate occurs. Raman spectra of a rubredoxin-like oxygenase (isolated from p. oleovorans) will be used as a probe of active site changes during inhibitor binding. The mechanism of oxygen activation is approached from a semiempirical X alpha theory designed for transition metal complexes. BIBLIOGRAPHIC REFERENCES: H. Sambe and R. H. Felton, "A New Computational Approach to Slater's X alpha Equation", J. Chem. Phys., 62, 1122 (1975). L. D. Spaulding, C. Chang, N. T. Yu and R. H. Felton, "Resonant Raman Studies of Metallooctaethylporphyrins", J. Amer. Chem. Soc. 97, 2517 (1975).